Nosocomial infections are an important healthcare and economic burden in the United States. Their prevention is therefore important for decreasing patient morbidity and mortality and overall financial costs. Acinetobacter baumannii is a Gram-negative opportunistic pathogen and one of the most common causes of nosocomial infections worldwide. It frequently causes ventilator-associated pneumonia and septicemia and has become a particular problem in soldiers returning from Iraq and Afghanistan with wound injuries. High antibiotic resistance levels hinder treatment of these infections. Compared to other Gram-negative bacteria, A. baumannii is highly desiccation tolerant. This phenotype plays a major role in its transmission because patients and healthcare workers come into contact with contaminated surfaces and medical devices. Currently, the genetic mechanisms mediating desiccation tolerance in A. baumannii are unknown. The overall goal of this project is to identify and characterize factors that contribute to desiccation tolerance in A. baumannii. Since desiccation tolerance is a complex trait, I hypothesize that A. baumannii utilizes both conserved and novel mechanisms to tolerate water loss. The results generated from these studies may lead to new strategies for preventing and containing A. baumannii infections.